Making any creative endeavour is a risk. It's normal to feel nervous. I don't personally see why that should stop you.
I don't personally see "making a new thing with the same genre/vibe that builds on what readers reacted well to in one of my works" as being the same as "making a direct sequel". When I rebooted Fan Dan Go into Errant, the first thing I did was write a list of things readers reacted well to and that I wanted to keep...and then another list of things readers criticised and didn't like that I wanted to get rid of or change. I listened to my audience, but I chose my own solution, not "continue this" but "redo this, but do it better this time".
The problem with sequels is, people are generally only interested if they read all the way through the first thing. Are you satisfied making work that never gets a bigger audience than what you have? You can't even guarantee the current readers will stick around; sometimes people get bored or get busy with uni or kids or jobs, so there's a fairly high chance the sequel has a smaller audience than the work it follows. If you want to build an audience, you need to seek out new people.
Angel may have had a dedicated cult fanbase, but it was a much smaller one than Buffy and has largely been forgotten, because it had familiar characters to appeal to hardcore Buffy fans, but it lacked a lot of the things a wider audience could connect with about Buffy and that made it iconic. I don't think Whedon could have built a career on just milking Buffy sequels and spinoffs forever. Yeah, Firefly was a flop, but I think making something different was the right call, because then he tried writing comics, and that got him in with Marvel, and then... yeah, he ended up writing the Avengers movie and it was massive. He tried new things and took risks and it paid off.
If you're not reliant on the income your stories are already making to pay your rent, you have nothing to lose by trying new things and aiming for better. After reading your response, I still stand by that. I could have continued Fan Dan Go with its... like 150 odd subs on Drunk Duck and Smack Jeeves, probably with a bunch of them not really reading because time had passed and they were out of the habit of reading... and then lost everything because Smackjeeves went down, lol. But I didn't. I remade it into Errant; new platform, new format, new artstyle, new plot, major changes to the characters and lore... and it's got over 2500 subs, it's had a successful print kickstarter, it's on the Tapas Creator Bonus Program.
As the saying goes: "Nothing ventured, nothing gained".